Cambridge IGCSE Science - Combined 0653 — 2011 May/June Paper 3 · Variant 1

This document consists of 19 printed pages and 1 blank page. IB11 06_0653_31/5RP © UCLES 2011 [Turn over *1701562327* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/31 Paper 3 (Extended) May/June 2011 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 20. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 1 Dung beetles live in places where large herbivores, such as elephants, buffalo or cattle, also live. The beetles collect dung produced by the herbivores and make it into a ball, which they roll away and bury. They lay eggs on the buried ball of dung, so that when their larvae hatch they can feed on the dung. The adults also feed on the dung. Fig. 1.1 shows a dung beetle rolling a ball of dung. Fig. 1.1 (a) Dung beetles play an important role in the carbon cycle. Using the information above, suggest how dung beetles can help a carbon atom in animal dung to become part of a carbohydrate molecule within a plant. [3] (b) The buried dung adds nitrates to the soil. Explain how this can help plants to grow better. [2]

3 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (c) Farmers may use insecticides (pesticides that kill insects) on their land. (i) Explain why farmers use insecticides. [2] (ii) Using the information above, explain why using insecticides on land where cattle graze could reduce the growth of grass. [2]

4 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 2 The chemical formulae for some compounds (minerals) found in rocks are shown below. CaMg(CO3)2 dolomite KAlSi3O8 potassium feldspar NaAlSi3O8 sodium feldspar CaCO3 calcite (a) A white powder is known to be either potassium feldspar or sodium feldspar. Describe a test and its results which would enable a chemist to find out which of these minerals is contained in the white powder. [2] (b) Calculate the relative formula mass of calcite. Show your working. [1] (c) When dolomite is strongly heated, carbon dioxide gas is given off and a mixture of calcium and magnesium oxides remains. (i) The symbolic equation for this reaction which is shown below is not balanced. Balance the equation. CaMg(CO3)2 CaO + MgO + CO2 [1]

5 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (ii) Name the type of chemical reaction in (i) and state the evidence you have used to decide your answer. type of reaction evidence [2] (d) A student adds some water to some calcium oxide. She observes that an exothermic reaction occurs and an alkaline solution is formed. (i) State the ion whose concentration increases when calcium oxide reacts with water. [1] (ii) The student then adds dilute hydrochloric acid to the solution from (i). Write a word equation for the neutralisation reaction which occurs. [2]

6 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 3 In an experiment, weights were hung on a spring and the length of the spring measured. Fig. 3.1 shows a graph of the results. 100 80 60 40 20 0 0 1 2 3 4 5 load / N 6 7 8 9 10 length / mm Fig. 3.1 (a) Calculate the extension of the spring when a 4 N load is hung from it. Show your working. [1] (b) Explain the relationship between the load on the spring and the length of the spring when the load is increased from 0 to 10 N. [3]

7 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (c) Fig. 3.2 shows a wooden bird suspended from an identical spring. Fig. 3.2 The total length of the spring is 51 mm. (i) Use the graph in Fig. 3.1 to find the weight of the bird. Show your working. [1] (ii) The density of the wood used to make the bird is 0.8 g / cm3. Use your answer to (i) to calculate the volume of the bird in cubic centimetres. The gravitational field strength of the Earth is 10 N / kg. State any formula that you use and show your working. formula used working [3]

8 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 4 Fig. 4.1 shows a sperm cell. nucleus Fig. 4.1 (a) On Fig. 4.1, use label lines to label and name two structures that are found in all animal cells. [2] (b) Name the organ in which sperm are produced. [1] (c) An investigation was carried out into the oxygen use and energy use of sperm while they were at rest and while they were swimming. For each measurement, the researchers calculated the amount of oxygen and the amount of energy used by 109 (one thousand million) sperm. The results are shown in Table 4.1. Table 4.1 oxygen use / units per 109 sperm per hour energy use / joules per 109 sperm per hour resting sperm 24 46 swimming sperm 83 164 (i) Suggest why the researchers measured the oxygen use and energy use for 109 sperm, rather than for a single sperm. [1]

9 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (ii) Explain why more oxygen is used when the sperm are using more energy. [2] (iii) Calculate the total power output of a group of 109 swimming sperm. State the formula that you use and show your working. formula working [3] (iv) In order to reach an egg, a human sperm has to swim from the top of the vagina to an oviduct, through a thin layer of liquid. Explain how the shape of the sperm, shown in Fig. 4.1, reduces the energy required to swim this distance. [2]

10 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 5 (a) Nuclear reactors can be used in power stations to produce energy for generating electricity. (i) Suggest one advantage and one disadvantage of generating electricity in this way. advantage disadvantage [2] (ii) Describe what happens to an atom during nuclear fission. [1] (iii) Below is a newspaper article written by someone who has a poor understanding of radioactivity. There was a leak of radiation from our local nuclear power station yesterday. The radiation blew across farmland. It emits gamma particles which are harmful to wildlife. Write down one mistake reported in the article. Explain why this is a mistake. mistake explanation [2]

11 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (b) A badge made from photographic film can be used to check the exposure of the workers to radiation. A simple badge has two sections A and B for the detection of beta and gamma radiation. Fig. 5.1 shows a worker wearing his badge. section A section B badge Fig. 5.1 Fig. 5.2 shows the side view through the badge. plastic photographic film aluminium A B thin opaque plastic front cover front back Section A has a plastic absorber. Section B has a plastic absorber and a 4 mm thick aluminium absorber. Fig. 5.2 When the photographic film from the badge is developed, it turns black where it has been exposed to radiation. (i) Complete Table 5.1 to show whether the photographic film will turn black when exposed to beta or gamma radiations. Table 5.1 radiation will section A turn black? will section B turn black? beta gamma yes [2]

12 © UCLES 2011 0653/31/M/J/11 For Examiner's Use (ii) Explain why the badge can not be used to detect alpha radiation. [1] (c) Alpha, beta and gamma radiations behave differently when they are passed through an electric field. (i) Explain why gamma radiation is not deflected. [1] (ii) Explain why alpha and beta radiation are deflected in opposite directions. [1]

13 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use 6 (a) Air is a mixture of elements and compounds. The two main elements in air are nitrogen and oxygen. Nitrogen dioxide, NO2, is a compound of nitrogen and oxygen. (i) Complete Table 6.1 by writing M in the right hand column if the description refers to a mixture of nitrogen and oxygen or C if it refers to the compound, nitrogen dioxide. Table 6.1 description M or C nitrogen atoms are bonded to oxygen atoms relative amounts of nitrogen and oxygen can vary little or no energy change when formed from nitrogen and oxygen chemical properties are very different from either nitrogen or oxygen [2] (ii) The gases nitrogen and oxygen can be separated by fractional distillation from air which has been cooled and pressurised so that it turns into a liquid. Explain briefly how fractional distillation separates nitrogen and oxygen from liquefied air. [2] (b) Nitrogen and hydrogen can be made to react together to form ammonia, NH3. This reaction requires a solid iron catalyst and a high temperature. Explain, in terms of molecular collisions, why increasing the temperature increases the rate of reaction. [2]

14 © UCLES 2011 0653/31/M/J/11 For Examiner's Use (c) The diagrams in Fig. 6.1 show the outer electron shells of atoms of the elements hydrogen and sulfur. H S Fig. 6.1 When these atoms bond together, they form a covalent compound whose formula is H2S. Use the information shown in these diagrams to explain why the formula of the compound is H2S. You may wish to draw a diagram to help your explanation. [2]

15 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use 7 The smell of food cooking can cause a person's salivary glands to secrete saliva. (a) (i) Name this type of response to a stimulus. [1] (ii) Describe how the information about the smell of the food travels from the nose to the salivary glands. [3] (b) When food has been taken into a person's mouth, it is chewed by teeth and mixed with saliva. Describe how the molar teeth help in the digestion of food. [3] (c) Saliva contains the enzyme amylase. What is an enzyme? [2]

16 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 8 A student carried out an experiment to find which substances in the environment caused nails made of mild steel to become rusty. She selected three identical nails and placed them in sealed test-tubes, A, B and C, as shown in Fig. 8.1. dry air only A air and water vapour B nitrogen gas and water vapour C water Fig. 8.1 (a) Predict in which tube, A, B or C, the nail became rusty, and explain why the nail did not rust in either of the other two tubes. [3] (b) Stainless steel does not rust because it is protected by a very thin layer which contains chromium oxide. (i) Chromium oxide contains chromium ions, Cr3+, and oxide ions, O2-. Deduce the chemical formula of chromium oxide. Explain how you obtained your answer. [2]

17 © UCLES 2011 0653/31/M/J/11 [Turn over For Examiner's Use (ii) Explain why an oxide ion carries a double negative (2-) electrical charge. [2] (c) Steel is used to make the chain of a bicycle. To prevent rusting, the chain is covered by oil made of hydrocarbon molecules. The oil used to protect the bicycle chain contains mainly hydrocarbon molecules which do not contain any double bonds. steel chain (i) Describe a chemical test and its result that would show whether or not a hydrocarbon oil contained molecules with double bonds. [2] (ii) Suggest one property of a hydrocarbon oil which makes it suitable for use as a barrier to prevent rusting. [1]

18 © UCLES 2011 0653/31/M/J/11 For Examiner's Use 9 The speakers of three MP3 music players are being compared. (a) The speakers are tested to find the range of frequencies they produce. Table 9.1 shows the results. Table 9.1 speaker range of frequencies / Hz A 100 to 10 000 B 20 to 25 000 C 20 to 40 000 (i) What is meant by the term frequency? [1] (ii) Use the information in Table 9.1 to suggest why the music played through speaker A might not sound as good as the other two speakers. [1] (iii) Music played through speakers B and C sounds the same. Suggest a reason for this. [1] (b) Two speakers each with a resistance of 8 Ω are connected in parallel. Calculate their combined resistance. State the formula that you use and show your working. formula used working [3]

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20 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2011 0653/31/M/J/11 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2011 question paper for the guidance of teachers 0653 COMBINED SCIENCE 0653/31 Paper 3 (Extended Theory), maximum raw mark 80 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • Cambridge will not enter into discussions or correspondence in connection with these mark schemes. Cambridge is publishing the mark schemes for the May/June 2011 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0653 31 © University of Cambridge International Examinations 2011 1 (a) ref. to digestion / absorption (in dung beetle) ; ref. to respiration (in dung beetle) ; carbon dioxide into air / breathed out; carbon dioxide absorbed by plant ; carbon dioxide used in photosynthesis (in plant) ; [max 3] (b) nitrates / minerals absorbed by plant roots ; used for making proteins ; proteins used for making new cells ; [max 2] (c) (i) to kill / destroy, pests / insects ; which eat / damage, crop / grass for grazing ; increase yields ; [max 2] (ii) kill dung beetles ; dung not buried / nitrate (in dung) does not enter soil ; [2] [Total: 9] 2 (a) powder held in a flame / reasonable reference to flame test ; flame colour would enable powder to be identified / potassium (feldspar) – lilac / sodium (feldspar) – yellow ; [2] (b) 40 + 12 + 16 x 3 (= 100) ; [1] (c) (i) CaMg(CO3)2 CaO + MgO + 2CO2 ; [1] [allow multiples] (ii) (thermal) decomposition ; (heating) causes a substance to break down into simpler ones / calcium / magnesium oxide (and carbon dioxide) is (are) simpler substances than dolomite ; [2] (d) (i) hydroxide / OH– ; [1] (ii) calcium hydroxide + hydrochloric acid calcium chloride + water ;; [2] (LHS and RHS) [Total: 9]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0653 31 © University of Cambridge International Examinations 2011 3 (a) extension = 18 mm ; (58 – 40 = 18) [1] (b) proportional ; between 0 and 8 / 8.4 N ; curved section beyond elastic limit ; after 8 / 8.4 N permanent deformation ; [max 3] (c) (i) 2.4 N ; [1] (ii) mass = 240 g ; density = mass / volume ; volume = 240 / 0.8 = 300 cm3 ; [3] [Total: 8] 4 (a) label to cell membrane ; label to cytoplasm ; [2] (b) testis ; [1] (c) (i) single sperm quantities would be too small to measure ; [1] (ii) respiration ; oxygen combined with sugar to release energy ; [2] (word or correct balanced equation must show energy released) (iii) (formula) power = work / time OR power = energy / time ; (substitution) 164 / 60 × 60 ; (answer + unit) 0.046 / 0.05, W / J s–1 ; [3] (iv) pointed head / small head / streamlined; reduces friction / drag; idea that less (forward-acting) force required ; [max 2] [Total: 11]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0653 31 © University of Cambridge International Examinations 2011 5 (a) (i) no fossil fuels used up / no CO2 released / no global warming effect ; radiation leaks / nuclear waste problems / nuclear accidents ; [2] (ii) nucleus splits ; [1] (iii) “radiation blew across farmland” ; wind unable to deviate path of radiation ; OR “gamma particles” ; gamma is not particulate / owtte ; [max 2] (b) (i) radiation will section A turn black? will section B turn black? beta yes no gamma yes yes ;; [2] (ii) alpha is unable to penetrate the plastic / front cover ; [1] (c) (i) no (electric) charge ; [1] (ii) correct reference to oppositely charged particles ; [1] [Total: 10] 6 (a) (i) C M M C ;; (1 mark for each two correct) [2] (ii) oxygen and nitrogen have different boiling points ; liquefied air allowed to warm up / heated ; as temperature rises, the components boil off when their b.pt. is attained / owtte ; [max 2] (b) molecules have greater kinetic energy / move faster ; collide more frequently with one another / with catalyst ; reference to greater energy of collisions; [2] (c) idea that the atoms seek a noble gas configuration / full outer shell ; 2 electrons in full outer shell of H ; 8 electrons in full outer shell of S ; [max 2] (fully correct dot cross diagram scores both marks) [Total: 8]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0653 31 © University of Cambridge International Examinations 2011 7 (a) (i) reflex (action) ; [1] (ii) as electrical impulse ; along nerves neurones ; correct ref. to sensory / motor, neurone ; correct ref. to central nervous system / brain ; [max 3] (b) grinding / crushing ; increase surface area of food ; idea of easier access for enzymes ; [3] (c) catalyst ; protein ; speeds up / controls (metabolic) reactions ; [max 2] [Total: 9] 8 (a) (nail rusted in B) air / oxygen and water are present (together) / air and water needed for rusting ; no water / water vapour in A ; no air / oxygen in C ; [3] (b) (i) Cr2O3 ; idea of need for charge balance ; [2] (ii) ion has more (negative) electrons than (positive) protons ; the atom gains electrons ; two more ; [max 2] (c) (i) reference to bromine / bromine solution / potassium permanganate ; reactant decolourised if hydrocarbon contains double bonds / owtte ; [2] (ii) does not mix with water / air / oxygen ; sticks to chain / steel ; [max 1] [Total: 10]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2011 0653 31 © University of Cambridge International Examinations 2011 9 (a) (i) number of waves per second / unit time ; [1] (ii) less frequency range / high and low frequency sounds missing ; [1] (iii) the frequency ranges (for B and C / both) include the human hearing range / owtte ; [1] (b) 1 / R1 + 1 / R2 = 1 / R ; = 1 / 8 + 1 / 8 ; R = 4 Ω ; [3] [Total: 6]